The Hacker/Modular Overlap

Oooh, that could be a stage name. HMO.

I wanted to take a moment to digress a bit and go into what makes modular synthesis so rewarding to folks with a hacker mindset.

I’m not a musician. I have dabbled in bass, guitar, keys and drums, but as for formal training, I’ve had guitar and djembe lessons, and not a whole lot of them. But the thing about music is, if you LOVE music, it will find a way to move you in one direction or another.

I’ve had many thousands of dollars worth of equipment over the years from Korg, Kawai, Yamaha, Casio, Nord, Alesis, Peavey, PRS, Epiphone, Tascam, Moog, Ableton and many more. And they’ve all been very rewarding in their own way. But none of them has given me the sustained high that exploring modular synthesis has given me. My first exploration was a Moog Subharmonicon, which quickly grew into the entire Moog semi-modular trio of Subharmonicon, DFAM and Mother32. I realized that being able to tweak and modulate sounds and sequences on the fly on an intuitive basis would more than make up for the fact, for me anyway, that I have limited musical playing ability.

And when I expanded that setup to include specialized Eurorack modules like Clank Chaos, Castor & Pollux, and utility modules like mults and LFOs, I realized this was the space I needed to be in. The limiting factor for making music, for me, was always that without musical skill, there was only so much variety I was able to create in realtime. Sure, I could layer multiple track and create sonically rewarding pieces, but look — I work in tech all day long, and I pursue tech hobbies on the side as well. The last damn thing I want to do when I make music is drill down into menus and learn advanced software tools. I wanted something far more tactile, and something closer to magic. Rather than directly crafting a particular sound, I find value in combining functionalities and making the different components “influence” each other in unique and interesting ways. I find that when I start a session with modular equipment, it never ends up in the same place twice. Sometimes I’ll start with a keyboard CV value to start, and route it into one or five places. Sometimes I’ll take the audio from one component and throw it into another for further manipulation. I’m particularly drawn to the modules with an element of randomness or surprise, like the Clank Chaos or the QuBit Bloom.

I credit another DC540 member for triggering me to make some changes and fall even deeper down the modular rabbit hole. Now the semi-modulars are on their way out, and I got a new case to replace the non-portable homemade Ikea rack I was using before. I find myself imagining how this configuration could be taken completely portable, and actually considering replacing the brand new 24-channel mixer I just bought a few months back with something similar that fits in the box.

For a while I had a friend’s Minimoog Voyager. I loved how it combined the best of both worlds. You could easily choose presets, but you could make vast modifications to those presets by twiddling knobs, and then save those changes to your presets. A bit out of my league pricewise, though, unless I sacrificed much of my other gear.

Busy busy busy, FlipperZero and Proxmark3 RDV4

As I posted the other day, I recently received my FlipperZero. I learned that it would read my 26bit LF RFID cards, but not my 34bit LF RFID cards. I fed my info back to the developer(s) via github, we’ll see if improvements happen over time.

But during the process, I ended up using my Proxmark3 RDV4 to help troubleshoot, and ended up getting the latest, most maintained and seemingly most capable firmware.

What some people don’t realize about the PM3, like a lot of SDR type devices, is that the software consists of two parts — firmware for the unit itself, and client software that runs locally, connecting over the USB serial, to issue the commands to and receive replies from the firmware. This means that it’s critical, when you swap firmwares, to swap clients as well. Managing multiple firmware versions can be confusing for this reason.

In the process of troubleshooting, I realized was using the iceman firmware from a few years ago, and the official “stock” firmware, also from a few years ago, None of this firmware was able to give the developer dumps in the format requested. Turns out there’s a far more current build out there at https://github.com/RfidResearchGroup/proxmark3.git, and even flashing the bootrom has gotten easier. Just hold the button down while you’re plugging it in, and continue to hold it while entering the command to flash the bootrom. Seems that tactic also works if you’re having trouble flashing the firmware itself. Painless firmware flashes. I did this from a Macbook M1 Air, and it took a bit of fiddling to get all the requirements down, but once I did, it works like a breeze, and the pm3 client and pm3-flasher client are both in my path now.

Still bummed that I haven’t been able to read my cat’s RFID tag yet, but I’ll keep banging on it, and maybe eventually I’ll figure it out. No idea if the Flipper will be able to read that.

Next temptation: Maybe a dual RFID ring. They make nice looking rings that carry both LF RFID and a MiFare 1K “magic” tag. I wonder if many hotels are still using MiFare 1K. It’d be fun to clone my hotel room key to a ring.

I’ll probably have them both with me at the meeting tomorrow evening if anyone wants to experiment.

DC540 Meetup 3/21 In-Person

We’ll be meeting at Social House in South Riding tomorrow evening, starting at 1830 til whenever. A great opportunity for noobs and strangers to prove their worth for elevated Discord status and invites to the private meetups.

Bring badges, wear swag, show your defcon colors. We’ll be easy to spot. If the weather holds out as planned we’ll try to hang outdoors.

Flipper Zero on Day Zero

Finally got my Flipper Zero, been waiting it seems like forever for this cute little dangerous toy. So dangerous, in fact, that Ebay is prohibiting its sale. That’s fine. I’m not selling mine anyway.

First thing I tried was capturing a couple of RFID cards I had handy. The first one worked, and I was able to store it in the database for future emulation. The second one did not.

I started digging into why:

First theory: Well, maybe it’s just a weak reader. Let me go get my Dangerous Things RFID Diagnostic Card and see how strong the reader is. Hmm. Not registering at all. What on earth could that mean? Clearly it’s reading one card. Let me look closer…

Well dang. Maybe from now on I shouldn’t keep my RFID Diagnostic card in my wallet next to my gas card. Seems like I knocked one of the capacitors clean off. TANGENT: Fire off an email to Dangerous Things asking for the component value, put it on my to-do-list to replace either the component or the entire card.

Quick, fire off an uninformed Reddit post to see if other people are seeing this issue. Sure enough, the developer fires back. SOME EM4100 cards and SOME HID cards are supported. Recommends I open an issue on their github to give feedback so they can support more.

So now it’s time to search the basement for the Proxmark3 RDV4. Took a few passes, but eventually found it in the bottom of a bin from last time I shuffled surfaces. Oh wait, my current laptop doesn’t have the Proxmark software. Good news, I was able to install the Proxmark software (iceman fork FTW!) on the M1 with minimal effort. And then I flashed the Proxmark with the latest iceman firmware, and now I’m back in business. The difference between the two cards? The working card is 26-bit HID, and the unrecognized card is 34-bit HID.

Opened an issue on the FlipperZero github as requested, and now we wait.

Monday 2/28 HYBRID.

This week’s DC540 meetup will be HYBRID. In person for those who want to share a common space and a common table, and virtual for those who can’t make it out. Tune into the Discord for topics.

NEXT week, 3/7, will be virtual only due to stuff going on.

How Chatty Is Your Network?

I do a lot of closed network design for projects. Island networks for developer teams, with no internet, but all the collaboration accoutrements a productive team might need. Authentication, repositories, build systems, file sharing, email, SSO, etc.

Yesterday one of them blew up. The collaboration suite stopped working. My first theory was that something ran out of space. And I was right, but not the collaboration suite itself. Turns out the LDAP server which handles authentication ran out of space, and the collaboration suite died because it couldn’t contact the LDAP server.

But wait, why did the LDAP server run out of space? All it’s doing is LDAP and DNS.

And the journey begins.

A while back, I had disabled recursive DNS queries because someone’s chatty MS product was spewing so many DNS lookups that would never resolve, and those queries were subject to a timeout, and those backed up queries created a logjam that prevented legitimate queries for local assets from getting through. Disabling/disallowing recursive queries seemed to shut everyone up, since the queries were immediately denied rather than waiting for the timeout, so I moved on.

Yesterday’s problem was a bit more intense. Someone had pulled an email from outside the system into Outlook on the closed system. Not a problem, right? Well, Outlook is downright screwy sometimes. Just the act of doing that caused that user’s Outlook to spew over 600 DNS queries per second, and since the DNS server had defaulted to query logging, it resulted in 20+ GB of query logs, to the tune of 46 million queries in less than 60 hours.

This seemed slightly excessive to me.

I know I could have just turned off query logging, but I thought of another approach that might stop the noise without sacrificing query logging, because, you never know how that information might help. Also, that doesn’t STOP the traffic, it only stops recording the traffic. So I took all the domains from the chattiest queries — by far the highest was from that clearly broken Outlook process, an infinitely-repeating query to an outlook mobile / O365 address on msedge.net — and created fake authoritative zones on my DNS server. I was almost surprised that that shut things up immediately. Because I left query logging on, I could see an immediate effect. I guess an authoritative no is enough to shut things up in cases where a denied query might not.

All this is to say, really, I think 99% of people really have no idea just how much communication goes on behind the scenes in their so-called private networks. This is a set of clients that have never touched the Internet. Fresh out of the box, with updates applied from WSUS offline bundles, and I’ve got hundreds of thousands of queries to Facebook, Twitter, Ebay, Amazon, Google, MS and more. None of it was initiated by the user. This is all of that “user as product” bullshit.

February 21 Meeting Recap

Nice in-person meeting last night. One attendee brought his portable modular synth case. I wish we would have gotten around to plugging it in, I’m interested in the sounds of some of the modules.

Sorry to those who were hoping we’d be virtual as well. Maybe you had your own separate meeting. Maybe DC540 has forked now.

We discussed yet another new direction for this year’s badge. Sounds fun and intriguing. Even more so if people run with the idea.

A discussion came up about the state of CentOS replacements after CentOS’ shift to an upstream rolling distribution model. I thought I’d share this writeup by computingforgeeks, which summarizes the four main contenders, mainly in order to battle one member’s contention that “only four people use Rocky.”

Reasons for Upgrades

My two favorite reasons for upgrades are expanded capabilities and simplified workflow.

I recently upgraded my mixing board/recording console from a Tascam DP-24SD to the Model 24. They’re both 24-track recording consoles, but the operation is night and day.

First, the DP-24SD only has 8 real-time input channels. This is fine for someone who wants to lay down tracks one or several at a time, but not for someone like me whose primary limiting factor was “too many sound sources.” The Model 24 can actually receive 24 channels of audio at once. Bye bye rack-mount submixer, hello modular synth sound sources!

Second, while the DP-24SD was really capable, with panning, effect sends, per-channel EQ, etc., all of that was controlled in a menu. When your’re in a zone making bleep bloop sounds, it takes you out of the zone to have to navigate menus. The 24 has dedicated knobs for panning, FX send, EQ, etc. for each channel. It’s like the gear I learned to do this stuff on back in the day. Except now it records 24 tracks to an SD card.

The end result of these improvements is that making music gets me high again. Instead of frustrated menu-navving, I’m tweaking sounds and levels in real time and doing more, with less context-switching. It’s a more organic relationship between myself and my analog synths.

And yes, it’s messy. I find myself changing my wiring choices every time I fire it up. In real time. On the fly. Someday the semimodulars and the modular stuff will be closer together. Until then, here we are.

It’s a similar upgrade decision tree for the laser engraver. I found myself deciding not to try new things a few times because it would require a height adjustment. Two hex screws to loosen, move the laser head to the new height, and then tighten again. A recipe for stripped screws, and a pain in the butt. Found the plans for this on thingiverse, installed it, now changing the height is just turning the knob. SO much easier to adjust the height for wood, leather, aluminum, or even the roller attachment.

February 21, 2022: In-Person!

We’re opening up the basement for an in-person meetup tomorrow evening. The usual location at the usual time. Masking is still encouraged.

I’ve been working on calibrating and documenting the laser engraver settings. I also added a 3d-printed height adjustment mechanism, which is amazing. If you want to bring home a souvenir, open up GIMP and create yourself a business card. 84x54mm, or 54x84mm if you want it vertical. I have several colors of coated aluminum business card blanks to choose from, and I’ll be happy to burn you one while you’re here. This is from a recent commissioned request.

If we have enough cats to herd, we’ll talk about the official organization and maybe even elect a board. Bring a snack or bev to share if you’re so inclined, or just mooch. Your choice. We’re all family here.

If you’ve never been and you’ve been vetted and have the address, come on out. If you’re a complete stranger, consider getting to know us in the Discord for a meeting or two.